| 摘要 |
<p>PURPOSE:To reduce an optical fatigue of a photosensitive body, to eliminate a failure of picture image quality, and also to prevent the deterioration of a paper jam detecting capacity by using a light of a wavelength area for giving no optical fatigue to the photosensitive body, when detecting the paper jam of a transfer paper by projecting a light emitted from a light emitting element to the surface of the photosensitive body of an As.Se compound for forming an image, and detecting its reflected light. CONSTITUTION:An LED for emitting a light of a wavelength of <=650nm which generates no optical fatigue in a photosensitive body of an As.Se compound is operated through a power source Vcc and a resistance R1, its light is projected to the surface of a photosensitive drum provided with the As.Se compound photosensitive body, and its reflected light is detected by a phototransistor 18e. Its output is converted to a voltage by an operational amplifier 21, compared with a reference voltage by a comparator 22, and when it becomes lower than the reference voltage, a paper jam is detected. Since a light of a wavelength by which no optical fatigue is generated in the photosensitive body is used, a failure of an image quality and the deterioration of a paper jam detcting capacity, which are caused by the optical fatigue are prevented.</p> |
